Most likely the problem is the Controller power supply. Disconnect the J704 wire cable on the Controller board and with basic AC power applied to the transmitter, make sure we have the following readings; J704 Pin 1 +15Vdc (+/-1V), Pin 2 Ground, Pin 3 +5V(+/-0.5V), and Pin 4 -15V(+/-1V).
If the DC Votlages are not present, you will need a replacement power supply. The correct part number of the power supply is as follows:
540-0006 for the FM 500C1, FM 1C1, FMi 31, or the FMi 73.
540-0015 for the FM 2C, FM 3C, FM 4C, FM 5C, FMi 106, FMi 201, FMi 301, or the FMi 402.